Metabolic and hepatic phenotypes in sarcopenic obesity and impact of bariatric surgery.

Background & Aims: Sarcopenic obesity (SO) is associated with cardiometabolic disorders and steatotic liver disease and carries major health risks. We assessed the hepatic and metabolic clinical phenotype associated with SO in patients with obesity undergoing bariatric surgery (BS). We also evaluated whether weight-loss and metabolic improvement post-surgery differ between patients with and without SO.

Methods: 972 consecutive patients from a single-center BS cohort who underwent whole-body dual-energy X-ray absorptiometry (DXA) and peri-operative liver biopsy were included. SO was diagnosed using the AIM-SO score, an AI-assisted unbiased clustering algorithm based on body composition. One-year post-surgery, 862 patients were reassessed for AIM-SO score changes.

Results: Pre-operatively, 207 (21.3 %) patients were diagnosed with SO. These patients had significantly higher prevalence of type-2 diabetes (T2D), arterial hypertension and obstructive sleep apnea (OSA) compared to patients without SO (all p ≤ 0.003). Patients with SO had more severe liver damage: higher grades of moderate/advanced steatosis (64.2 % vs. 47.3 %), steatohepatitis (44.4 % vs. 32.3 %) and advanced fibrosis (12.1 % vs. 6.0 %) (all p ≤ 0.01). One-year post-BS, 58.5 % of patients had remission of SO. Patients with persistent SO exhibited less weight-loss than those with SO remission (-23.8 kg vs. -29.1 kg, p < 0.001) and had lower rates of remission for T2D (41.9 % vs. 69.8 %), arterial hypertension (20.8 % vs. 45.3 %), and metabolic syndrome (47.6 % vs. 75.0 %) (all p ≤ 0.009).

Conclusion: The DXA-based AIM-SO score identifies patients with SO who are at greater risk of hepatic and cardiometabolic comorbidities, and predicts less favorable weight-loss and metabolic improvements post-BS.